Generally speaking, a thin-film transistor liquid crystal display (TFT-LCD) is manufactured mainly in three processing parts, including a thin-film transistor array engineering, a cell engineering, and a module engineering. Among which, the thin-film transistor array engineering is by forming an array-shaped thin-film transistor circuit onto a glass substrate.
A conventional thin-film transistor circuit is fabricated in five steps of mask fabrication with five masks. As the requirements of large-sized flat panel displays grow, masks utilized for manufacturing the large-sized flat panel displays have to be enlarged accordingly. Therefore, it is difficult to lower the cost for fabricating the large-sized flat panel displays subjected to the quantity and cost of the masks. Moreover, each mask fabrication step may spend more time in photoresist-coating, soft bake, hard bake, exposure, developing, etching, and photoresist removal.
Therefore, reducing the number of masks and steps of mask fabrication is an important aspect in this industry.